1. Field of the Invention
The embodiment discussed herein is related to a hybrid recording device that has a non-volatile semiconductor memory and a recording magnetic disk.
2. Description of the Related Art
Recently, hybrid recording devices each of which has a non-volatile semiconductor memory mounted therein together with a recording magnetic disc have appeared on the market. One of the hybrid recording devices is designed so that the non-volatile semiconductor memory is treated equally with the recording magnetic disk and data are arranged in the recording area of any one of the non-volatile semiconductor memory and the recording magnetic disk (see Japanese Laid-Open Patent Publication No. 6-314177).
In general, recording devices treat all data equally. On the other hand, in an external device (host computer) for transmitting/receiving data to/from a recording device, an access frequency of data, the level of importance of data, etc. are recorded in a policy table and managed while bringing each data with its meaning/treatment.
Accordingly, when access target data in a recording device is accessed at a high access frequency, it is desired to increase the access speed for the data, and when the level of importance of access target data is high, it is desired to prevent occurrence of an access error due to data loss or data breaking.
As described above, the hybrid recording device has a recording magnetic disk and a non-volatile semiconductor memory. These two recording media are effective to redundancy of important data if the recording media are made to hold the same data, and also effective to speed-up of data access by setting the non-volatile semiconductor memory to the access target.
However, the conventional hybrid recording device arbitrarily records data over the whole recording area of the non-volatile semiconductor memory irrespective of the meaning (intent and/or treatment) which the above external device has with respect to data although the hybrid recording device has both the recording magnetic disk and the non-volatile semiconductor memory. Therefore, there is a problem that optimization information of a data access system (the level of importance, the access frequency, etc. to be managed in the policy table by the external device) of each data owned by the external device cannot be reflected to the hybrid recording device as the difference of the recording control system.